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  • 1
    Electronic Resource
    Electronic Resource
    Abundances in the interstellar medium (1992)
    Springer
    The astronomy and astrophysics review 4 (1992), S. 1-33 
    Details
    ISSN: 1432-0754
    Keywords: Isotopes-Galaxy ; Evolution of-Interstellar Medium ; abundances
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Recent developments in the theory of element production and the chemical evolution of the galaxy are presented. Following this, observational data and their interpretation are given. A case by case analysis of results for D, He, Li and CNO isotope data in the disk and center of our galaxy is presented; previous results for element gradients are also summarized. The primordial abundances of D and He cannot be directly obtained from observations; corrections for stellar processing are discussed. From these data and the Li abundances, it appears that the abundance of the light elements is consistent with the standard big bang. In agreement with previous results, the range ofη, the baryon to photon ratio, is 5–8 10−10. If the amount of non-baryonic matter is small, these results indicate an open universe, in the standard big bang model. New data show a gradient in the (12C/13C) and (16O/18O) ratios with galactocentric distance, DGC. The presence of a gradient in the (14N/15N) ratio is less clear and there is no measurable gradient in the (32S/34S) ratio. In the interstellar medium near the sun, the carbon isotope ratio is −20 percent lower than the solar system ratio. This indicates that there has been only a moderate amount of enrichment of the nearby interstellar medium since the formation of the solar system. These results and previously determined galactic element gradients are interpreted in the framework of chemical evolution models. Delayed recycling of nucleosynthesis products is essential for the correct interpretation of the results. Comparisons of data with galactic evolution models are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00873568
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  • 2
    Electronic Resource
    Electronic Resource
    Burst testing of condoms. I. Basic features of the force-deformation curve of latex-rubber condoms (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Biomaterials 3 (1992), S. 117-122 
    Details
    ISSN: 1045-4861
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Inflation of a rubber condom involves biaxial deformation of the material which can be modeled by the use of an appropriate strain-energy function. Force versus deformation data for uniaxial extension of strips of condoms were used to determine the parameters for Ogden's form of a strain-energy function. These parameters were then used to fit experimentally obtained burst test data to a stress-strain equation formulated for inflation of condoms in a burst test. Experimental data on inflation of condoms agree well with theoretical curves verifying the applicability of the biaxial stress-strain equation to the particular strain-energy function on which it is based.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jab.770030207
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Multiple transitions in a dimethacrylate network (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 40 (1990), S. 1195-1208 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Triethylene glycol dimethacrylate, TEGDM, was cured to various dose levels (0.15-2.0 Mrad) by γ-irradiation at 40°C and its dynamic mechanical properties were evaluated. The resultant products had up to four transition phenomena dependent upon dose. The highest temperature transition (IV) was due to the ultimate glass transition. Transition III (ca. 40°C) was due to additional reaction occuring just above the cure temperature. Transition 1 (ca. -60°C) occurred at low doses and was associated with residual monomer. Transition II (ca. -10°C) is due to association of —(CH2CH2O)— units in TEGDM monomer, and the associated regions persist in the crosslinked polymer.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1990.070400710
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    Paper (German National Licenses)
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